1: libc {
    2:   GLIBC_2.1 {
    3:     # functions used in other libraries
    4:     __backtrace; __backtrace_symbols; __backtrace_symbols_fd;
    5: 
    6:     # b*
    7:     backtrace; backtrace_symbols; backtrace_symbols_fd;
    8:   }
    9:   GLIBC_2.2 {
   10:     # These are to support some gcc features.
   11:     __cyg_profile_func_enter; __cyg_profile_func_exit;
   12:   }
   13:   GLIBC_2.3.4 {
   14:     __chk_fail;
   15:     __memcpy_chk; __memmove_chk; __mempcpy_chk; __memset_chk; __stpcpy_chk;
   16:     __strcat_chk; __strcpy_chk; __strncat_chk; __strncpy_chk;
   17:     __sprintf_chk; __vsprintf_chk; __snprintf_chk; __vsnprintf_chk;
   18:     __printf_chk; __fprintf_chk; __vprintf_chk; __vfprintf_chk;
   19:     __gets_chk;
   20:   }
   21:   GLIBC_2.4 {
   22:     __fgets_chk; __fgets_unlocked_chk;
   23:     __read_chk; __pread_chk; __pread64_chk;
   24:     __readlink_chk; __getcwd_chk; __getwd_chk;
   25:     __recv_chk; __recvfrom_chk;
   26:     __realpath_chk; __ptsname_r_chk; __wctomb_chk;
   27:     __stpncpy_chk;
   28:     __wcscpy_chk; __wmemcpy_chk; __wmemmove_chk; __wmempcpy_chk; __wcpcpy_chk;
   29:     __wcsncpy_chk; __wcscat_chk; __wcsncat_chk; __wmemset_chk; __wcpncpy_chk;
   30:     __swprintf_chk; __vswprintf_chk; __wprintf_chk; __fwprintf_chk;
   31:     __vwprintf_chk; __vfwprintf_chk; __fgetws_chk; __fgetws_unlocked_chk;
   32:     __confstr_chk; __getgroups_chk; __ttyname_r_chk; __getlogin_r_chk;
   33:     __gethostname_chk; __getdomainname_chk; __wcrtomb_chk; __mbsnrtowcs_chk;
   34:     __wcsnrtombs_chk; __mbsrtowcs_chk; __wcsrtombs_chk; __mbstowcs_chk;
   35:     __wcstombs_chk;
   36: 
   37:     __stack_chk_fail;
   38:   }
   39:   GLIBC_2.5 {
   40:     __readlinkat_chk;
   41:   }
   42:   GLIBC_2.7 {
   43:     __fread_chk; __fread_unlocked_chk;
   44:   }
   45:   GLIBC_PRIVATE {
   46:     __fortify_fail;
   47:   }
   48: }